Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**tony123****Member**- Registered: 2007-08-03
- Posts: 189

For a positive integer,

, we define N! (read N factorial) tobe the product of all the integers from 1 to N. Thus:

It is clear that N! will end in a zero if N is larger or equal to

5. For big values of N, N! will end in many, many zeros.

How many zeros will end in?

*Last edited by tony123 (2008-09-13 09:38:07)*

Offline

**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

75/5 + 75/5² = 18.

Why did the vector cross the road?

It wanted to be normal.

Offline